In the past year, we have focused on understanding how ER morphology and arrangement influences its function in vivo. We are using both the central nervous system and male testes as two systems to perform live and fixed analysis of ER behavior. We have uncovered an exciting link between centrosomes and ER segregation in both symmetric and asymmetric mitosis. Most interestingly, we find that the ER is asymmetrically segregated in neural stem cells. This asymmetry occurs while the centrosomes and spindle look symmetric, suggesting that the ER asymmetry is a highly regulated process. We are currently disrupting centrosome function and analyzing ER distribution and function.